In sites and factories of various works, an worker avoids dangers from a flying object or a falling object as well as danger of falling by wearing a safety hat before such a danger happens, but the safety hat steams the worker's head with sweat by wearing the safety hat for a long time during summer time or hard work with a large quantity of labor. The steamed condition not only makes the works painful but also lowers the working efficiency.
As an attempt to provide the safety hat with air permeability, there has been known a safety hat formed by mesh or mesh porous materials so that absent areas are alternately positioned (see patent document 1). There have been other attempts to provide a working helmet or a riding helmet with air permeability by using air ventilation equipment (see patent documents 2 and 3). However, these safety hats do not have any protection from rain for outdoor use.
Although there has been disclosed a helmet having air permeability and protection from rain at the same time (see patent document 4), it is hard to achieve the original purpose of a helmet to protect a human head since there is possibility of a flying or falling object entering into the helmet and the helmet may not be strong enough due to fine pores provided in the side portions of the helmet body. The helmet does not have sufficient protection from rain because rain water may enter into the helmet when a worker bends himself to work.
Inventors of the present invention have suggested a safety hat including a double-structured hat body as a safety hat with air permeability and protection from rain (see patent document 5), but the double structure forces the safety hat to increase weight. Next, the inventors suggested a safety hat comprising a hat body having air conduit pores penetrating internal and external walls thereof, a drainage passage provided along the internal wall of the hat body to discharge water coming into the hat body through the air conduit pores, and air vent pores formed on the upper side of the drainage passage in the cross-section perpendicular to the water draining direction (see patent document 6). The safety hat was light in weight and excellent in terms of the rain protection, but there was still a room for improvement in terms of air permeability. The inventors then suggested a safety hat having a flow channel formed in the right and left side walls of the hat body, flowing ambient air in longitudinal directions and having a weathering structure, and the flow channel being connected to the internal of the hat body at the top portion of the hat body (see patent document 7), but the bottleneck of the safety hat is also how to reduce the weight.    [Patent document 1] Utility Model Publication No. SHO60-143736    [Patent document 2] Utility Model Publication No. SHO58-7832    [Patent document 3] Utility Model Publication No. HEI1-94430    [Patent document 4] Utility Model Publication No. SHO42-20108    [Patent document 5] International Publication No. WO95/28101    [Patent document 6] International Publication No. WO98/23176    [Patent document 7] Patent Publication No. 2000-303246